All currently avalable concrete creep predicting models cannot describe well the creep of a concrete structure because they all leave the effects of additives out of consideration.The purpose of this work was to modif...All currently avalable concrete creep predicting models cannot describe well the creep of a concrete structure because they all leave the effects of additives out of consideration.The purpose of this work was to modify model B3 for overcoming this deficiency.We tested thirteen specimens of C40 and C50 concrete with additives,out of which nine were for creep and four for shrinkage tests over a 700 d period under controlled temperature.We compared the experimental results for creep and shrinkage with those obtained by using model B3,and derived modification terms through regression analysis.Based on the experimental results of identical specimens under varied stress levels,we also derived a function considering the effect of stress level on creep.It is suggested that the creep prediction models without adjustment should not be used for modern concrete with a variety of additives.展开更多
Thirteen specimens were tested out of which nine were for creep of sealed concrete and four for shrinkage test,for a period of 700 d under controlled temperature condition.The experimental results for creep and shrink...Thirteen specimens were tested out of which nine were for creep of sealed concrete and four for shrinkage test,for a period of 700 d under controlled temperature condition.The experimental results for creep and shrinkage were compared with creep and shrinkage computation model B3 and distinct discrepancies between observed and calculated creep and shrinkage strains were observed.Based on regression analysis,modification on B3 model has been formulated which will be applicable at least for concrete of characteristics strength of C40 and C50 with additives.Besides,on the basis of observation on identical specimens with varied stress strength ratio,a function is generated which accounts effect of stress strength ratio on creep.Finally,Civil Engineering community is suggested not to follow the creep prediction models without correction at least for modern concrete,as they do not account the effect of additives on its compliance function.展开更多
文摘All currently avalable concrete creep predicting models cannot describe well the creep of a concrete structure because they all leave the effects of additives out of consideration.The purpose of this work was to modify model B3 for overcoming this deficiency.We tested thirteen specimens of C40 and C50 concrete with additives,out of which nine were for creep and four for shrinkage tests over a 700 d period under controlled temperature.We compared the experimental results for creep and shrinkage with those obtained by using model B3,and derived modification terms through regression analysis.Based on the experimental results of identical specimens under varied stress levels,we also derived a function considering the effect of stress level on creep.It is suggested that the creep prediction models without adjustment should not be used for modern concrete with a variety of additives.
文摘Thirteen specimens were tested out of which nine were for creep of sealed concrete and four for shrinkage test,for a period of 700 d under controlled temperature condition.The experimental results for creep and shrinkage were compared with creep and shrinkage computation model B3 and distinct discrepancies between observed and calculated creep and shrinkage strains were observed.Based on regression analysis,modification on B3 model has been formulated which will be applicable at least for concrete of characteristics strength of C40 and C50 with additives.Besides,on the basis of observation on identical specimens with varied stress strength ratio,a function is generated which accounts effect of stress strength ratio on creep.Finally,Civil Engineering community is suggested not to follow the creep prediction models without correction at least for modern concrete,as they do not account the effect of additives on its compliance function.
